Inflatable boat and method of making same



Oct. 8, 1946. u s p 2,4Q8,789

INFLATABLE BOAT AND METHOD OF MAKING SAME 3 Sheets-Sheet 1 Filed March 11, 1942 INVENTOR AUGUST awn/10.4

\ v ATTORNEY Oct. 8, 1946. A; G. LUISADA 2,408,789

' INFLATABLE BOAT AND METHOD OF MAKING SAME 3 Sheets-Sheet 2 Filed March 11, 1942 1 INVENTOR AU5U57' 6. LU/SADA ATTORNEY 1946- A. G. LUISADA INFLATABLE BOAT AND METHOD OF MAKING SAME Filed March 11, 1942 3 Sheets-Sheet 3 B Wm.

ATTORNEY INVENTOR. Ava/5r s. LUIS/IDA.-

Patented Oct. 8, 1946 UNITED STATES PATENT oFFicE INFLATABLEVBOAT AND METHOD or MAKING SAME August G. Luisada, New York, N. Y.

Application March 11, 1942,

29 Claims.

This invention relates to inflatable boats and to methods for producing thesame.

A primary object of the invention is to provide a novel method for producing inflatable boats in a simple and inexpensive manner.

Another object of the invention resides in the provision of a method for producing inflatable boats which are stable, have minimum water resistance, and withstand injurious scuffing.

Reference is made to the accompanying drawings in which invention. Said drawings form the basis for the following specification from which the objects of the invention will be more clearly realized.

In the drawings:

Fig. 1 is a diagrammatic cross-sectionalview of one form of inflatable boat according to the invention. i

Fig. 2 is a similar view of the right-hand portion of Fig. l in deflated condition showing one manner of forming thereof.

Fig. 3 is a similar view of said right-hand portion showing another manner of forming thereof.

Fig. '4 is a side elevational view of said righthand boat portion in the condition of either Figs. 1 or 2 and indicating the lines of cutting said portion.

Fig. 5 is a fragmentary cross-sectional View of a portion of Fig. 1 showing the physical structure according to Fig. 2.

Fig. 6 is a similar view accordingto Fig. 3.

Figs. 7,8 and 9 are fragmentary cross-sectional diagrammatic views illustrating types of fabric weave employed in forming the parts of the structure of Fig.3.

Fig. 10 is a of another form of inflatable boat according to the invention. v

Fig. 11 is a similar View of the right-hand portion of Fig. 10 in deflated condition.

Fig. 12 is a fragmentary deflated bottom plan view of said boat'portion.

Fig. 13 is a diagrammatic cross-sectional View of still another form of inflatable boat according to the invention.

Fig. 14 is a plan either the right orv view, in deflated condition, of left hand portion of Fig. .13.

Fig. 14a is a diagrammaticcross-sectional view thereof. I

Fig. 14b is a-diagrammatic.fragmentary view of a modified cross-section but drawn to an enlarged scale,

Fig. 15 is a diagrammatic longitudinal sectional view of the'boat shown in Fig.14. Fig. 16 is a plan view of said boat.

diagrammatic cross-sectional view are illustrated various forms of the onboth sides by impervious material.

boat being both Serial No. 434,241

2 .Fig. 1''! is a diagrammatic cross-sectional view, in partially inflated condition, of yet another form of inflatable boat according to the invention.

Fig. 18 is a diagrammatic sectional view of an inflatable boat such as shown in Figs. 1 and 10. Fig. 19 is a side view thereof illustrating a comparatively foreshortened boat.

Fig. 20 is a diagrammatic sectional view of an inflatable boat each as shown in Fig. 17.

Fig. 21 is a side view thereof illustrating a com.- parative foreshortened boat. Fig- 22 is a perspective view of a complete inflated boat constructed in accordance with the invention and as shown in diagrammatic cross section in Figs. 1, 2, 3, and 4. v

The instant method is particularly characterized by the forming of the air chambers and other. consituent parts of the boat before they are made air-tight. The invention consists in so designing these air chambers that they lie flat, so that they can be treated as easily as a single fabric, and made air-tight either directly--as one would do for coating a fabric, or superimposing upon the outer surfaces of the air chamber, airimpervious sheets and passing them through a doubling calender or the like. The single units are united together while still unvulcanized and in flatv condition to produce a preferably flatlying deflated boat which can then be vulcanized in this condition. The advantages of this method are obvious when it is realized that tedious assembling and joint tightening are obviated and speeding up of production eliminated. The work, instead, is performed entirely on the simplest machines such as doubling calenders or the like. The air chambers and other constituent parts of the boat mentioned above may at times hereinafter be referred to as units, and the word unit will be used as meaning any section of a boat which ismadeup as a component and which has been substantially covered The flatlying hollow units or air chambers may bemade mechanically without handwork, i. e., by weaving.

To carry out the present method. novel ways are employed to produce flat-lying hollow units which, when inflated, will bend substantially out of the plane in which they were lying when produced, said bending with respect to the finished longitudinal and transverse. The transverse transition to a bent hollow body, is achieved by so designing the cross-section that the parts of one or more tubes forming the infollows. Costly handwork is a side of a boat are shorter than the parts of the same tubes forming the outside of the boat while the total width of the fabric comprising said inner and outside parts are exactly co-extensive. The manner of constructing such hollow bodies or units will be disclosed in accordance with the chosen examples. The lengthwise deformation of the hollow bodies may be accomplished in other ways. It is not possible to make one of the fabrics of greater extent than the other When making a fiat-lying hollow body, but it is possible to so construct such fabric that when inflated one of them will expand under the stress of the air-pressure to a predetermined extent longer than the other, without impairing its tensile strength.

As one example of the invention, a method is explained which enables the construction of a boat by weaving or sewing only straight outlined cells or units or forming tubes of uniform diameter, the outlines of which are run only in the warp or weft direction. Hence, these fabrics can be woven on the simplest looms such as the dobby looms. When the structure is made by sewing, multiple head sewing machines can be used to produce, simultaneously, a plurality of parallel seams. By either method, a streamlined shape may be obtained after inflation of the boat which combines with maximum stability, features superior to that of the existing types. The method provides the possibility of subdividing the air chambers in any number of air-tight compartments that may be desired. I

One manner of obtaining such a structure is illustrated in Fig. 1 which is made in the following manner.

Reference is first made to Figs. 3, 4 and 6. A plurality of fabric tubes 25, 26, 21, 28, 29 and 35 are formed in any well-known manner, but are preferably woven. These tubes may vary in size according to the cross-sectional shape of boat desired. They may then be given a coating of tacky consistency by means of which they will adhere to each other and to outer rubberized sheeting or any air and water-impervious sheetmg.

The tubes are arranged in such a manner that the circumference of each tube is divided by folding into two equal parts. Each of these equal parts contains a portion which will combine to form the outside portion of the boat and another portion which will form a diaphragm or a bulkhead of the finished structure; for instance, the distance 49, l plus the distance], 2 shall equal the remainder of the circumference of the tube, i. e. 49, H plus ll, 2. In the tube 4| which forms the chine, the folding edges 8 and 9 are so disposed that the sum of the two diaphragms 4, 9 and 5, 8 and the portion 4, equal the remainder of the circumference of that tube or chine 9, 8. Forany number of adjacent tubes, the same relation must be true throughout the whole structure, for instance, 5, 8+8, 1 equals 5, 6+6, 1. And so the sum of all of the corresponding parts will be equal, as the sum of parts 49, I, 2, 3, 4, 5, 6, l2 equals the sum of l2, 1, 8, 9, In, H, 49, so that the structure Will lie fiat when deflated.

The'tubes to are arranged as in Fig. 3 wherein'portions 3i thereof are overlapped. It will be noted that tube 25 is overlapped on tube 26 which is overlapped on tube 21 and that tubes 30, 29, and 2B are similarly overlapped, the last of these being also overlapped on tube 27.

V This structure is now provided with a seam of such subdivision with carryover threads 38 to form along the line 49 and the parts 56 and 5| are cut away. If more than two separate chambers are desired, the structure according to Fig. 3 may be divided into two or more parts, the seams uniting only those parts which together form one air chamber. Between these air chambers, an airimpervious sheet is laid fiat, and the unit comprising one-half of the boat, will be laid again co-extensively as illustrated-in Figs. 3; and 4, so that the seam 49, composed now of several independent parts, again forms one continuous line.

An advantageous example in several respects would be along the diaphragm 9, 4. The body of the bottom consisting of 49, It, is, S, 4, 3 2, I would be separated by an airtight sheet or coating along 9, 4 from the side wall of the boat formed by 9, 8, 1, l2, 6, 5, 4. In this way, two such structures or units formed each by three tubes with equal length of diaphragm at equal distance, compose one-half of the boat.

To this arrangement of tubes are applied the outer airand water-impervious sheets 32 and 33 which are preferably rubberized fabric. The edges 34 and 35 of the sheets are preferably extended as shown, so that they may cohere to each other with no intervening fabric layer as shown in Figs. 1, 5, and 6. Thus the inner fabric parts are enclosed completely in the outer rubberized fabric. This application of the outer sheets constitutes a doubling operation that can be performed rapidly and economically on a doubling calender by application of pressure. In order that a doubling calender may be utilized, it is essential that all the parts lie flat.

This structure illustrated in Figs. 3 and 4 forms the right side of the boat of which Fig. 1 is a cross-section. Another such half boat made up in same manner represents the symmetrical lefthand side of the cross section shown in Fig. 1.

In making the tubes 25 to 30, it is intended that the contacting walls 38a be air-pervious to afford circulation of air among the tubes whereby infiation of all of them. may be simultaneous. Hence, the tacky coating is of such nature as to facilitate the mentioned coherence without impairing air-perviousness.

In the above manner a structure is formed which is cellular and completely sealed.

Instead of the use of separate tubes, the structure may be woven completely except for the outer sheetings, on a dobby loom. This is best seen'in Figs. 2 and 5, wherein the loom is arranged to weave the parallel portions 36 and 37 the cells, 39, 4e, 4|, 42, 43, and 44, each respectively comparable peripherally to the tubes 25 to 30. "Thus the walls 35 and 37 comprise Woven fabrics and the portions 38 carry over threads readily affording free air circulation among the cells 39 to 44. The structure may also be produced on a Jacquard loom, in which case the whole structure shown in Fig. 4 may be completely woven without seams, thus obviating the seam 49. The rubberized sheetings 32 and 33 are applied as before described.

Fig.2, of course, has been drawn somewhat opened so th-estructure thereof may be seen, but it is obvious that its formation is such that the walls 36 and 31 are co-extensive and of the'same length, and that the structure will lie flat and that when inflated, the, pressures throughout the communicating air chambers will be equalized.

Obviously, a similarstructure or unit may be for instance 55, will stantially according produced by sewing between two sheets 36 and 31;

partition 38.

'It' will also be seen that the structure shown either in Fig. 2 or in Fig. while woven orbuilt in flat condition, will inflate to the transversely bent cross-section shown in Fig. 1.

Fig. 4 shows either of the above-described structures in plan View and shows a typical line 49 along which the parts 50 and Bi may be cut away to form the boat shape. Two such structures'may then be secured to each other by adhering them along the surface of partition or diaphragm 53. This also is accomplished while all the parts are flat and theentire article may then be'vulcanized in flat condition, and the boat is ready for inflation. 7

While this disclosure deals with a boat which maybe inflated in halves,.it'is"apparent that the partition 53 may be eliminated as a bulkhead so that the, entire boatmay be inflated at one time. In this case the inner air-impervious sheet may end along the line l, so that the air may communicate through the air-pervious partition 53 of the boat when inflated as shown in Fig. 1.

Because the internal pressure is equal in all directions, the air causes each cell to seek a cylindrical form as shown. The cells are defined by the carryover threads 33. Because of the manner in which t 1e structure is woven, the'cell Al has a shorter exposed side 54 and a longer one 55. Hence the structure will bend, upon inflation, as shown, to form a bottom and sides 51.

Considering the shape of the inflated boat in a geometrical manner, it was desirable to provide the shape which is obtained by rotating the outline of half'the cross-section, for instance the right half shown in Fig. 1, around an axis parallel to the lines X and Y. This axis is inclined because an upraised bow andstern are desired in order to imitate or to reconstruct the traditional ship shape. By this bending the portions or arcs which are furthest away from the axis, as have a greater length than the portions or arcs 555- which are nearer to the axis. The difierence in length between the arcs will be greater as we approach the axis, as for instance in boats whichare short in proportion totheir width. A comparatively longer boat can be made when all parts are woven uniformly if a stretchable fabric is chosen for its construction. Every woven fabric has a certain elasticity. Therefore, a shape like that illustratedin Fig.

4 or longer with respect to its width, may be ob tained with any fabric. It may be desirable, however, to make the boat shorter in relation to its width. Accordin to this invention this is possible by providing a greater stretch in those portions of the weave which are to form the portions that are furthest away from the bend,- ing axis when the boat is inflated. For instance, such portions are shown at the right'of the line Y. n smaller amount of stretch is requiredbetween the lines X and Y andno stretch in the portion at the left of X. Thus,'the portion left of X can be woven according-to Fig. 7, the portion between X and Y substantially according to Fig. 8, and the portion to the right of Y, subto Fig. 9. 'The warp thread represented in each of these figures will shrink most in Fig. '7, less in Fig. 8, and still less in Fig. 9, so that when they are taken from the same weavebeam, the l--l weave in shortest and the 3-3 weave in Fig. 9, the longest.

In other words, when thefabric is roduced, the threads have the same lengthin all j p0r--.

Fig. 7 Will be the tions; but by changing the width indifferent 'por-g tions of the fabric, as illustrated in Figs. '7, 8 and 9, the various portions of 'the' fabric were given different degrees of 'extendability. The degree of extendability in the three different portions of'the fabric had been definitely pro-determined v in order to accommodate the fabric when extended to thecurvature required by the design of the finished boat. The exact degree of extendability necessary for the purpose can be pre determined and the actual expansion is obtained by inflation of the boat.

It win, therefore, be obvious too, that if the bottom is separated from the sidewall as referred strength of the used material to'the stress, which results in economy of material.

From what is seen that the hollow body which has acrosssection shown on the right side of Fig. land constructed according to Figs. 2 or 3, or in any commensurate manner, will bend when inflated around an axis-parallel to the lines X or Y according to "the purpose for which made. This feature provides the longitudinal bendin referred to above. It is obvious that this'efiect can be obtained in other manners than by changing the weave pattern as illustrated in Figs. 8 and 9. This method is merely the simplest one than can be performed on an ordinary Dobby loom.

It may be desirable to make boats that generally conform to the traditional surrounding tube type. In this case, another example for carrying out this invention is disclosed in Figs. 10, 11, and 12. The right side of Fig. 10 represents a cross-section which when deflated, will lie flat as shown in Fig. 11.

As seen in Fig. 11, a cellular boat portion is formed with outer walls til andfil of equal length and with carryover threads 62 forming the cells 63, 64, 65, 66 and 61. So that this structure and that of Figs. 1 and 2 may be better followed, a point-to-point comparison will be made of Figs. 10 and 11. Starting with point wand following around the periphery of Fig. 11, there are points I), c, d, e, f, g, h, i, a and k. These points on Fig. 10 are respectively A, B, C, D, E, F, G, I-L'I, J and K. Fig. 12 being in'plan, these points become lines and are designated as in Fig. 10."

The'transverse bending of this cross-section is obtained by constituting the inner portions of single compartments shorter than the outer portions of the same compartments. This is obtained here by augmenting the dimension of the tubes from thecenter outwardlyso thata relatively thin bottom is obtained which curves up and ends with the comparatively thick surrounding tube 63. This boat presents another example of design of an inflatable unit which is flat when deflated and is bent transversely to a shape substantially different from plane, when inflated. Instead; of arranging the partitions to extend in opposite directions, when deflated, as in Figs. 1, 2, 3, 4, they maybe arranged to extend all in the same direction as in Figs. 10 and 11, where it will be seen, the partitions or diaph'ragms are made wider as they progress from the center of the boat outwardly. All the partitions as well as the outer surfaccsare plane andttherefore,v it is described above, it will be clearly possible to subdivide the structure along any partition to provide a bulkhead if desired.

In order to make it possible to have an inflatable boat assume a fiat condition when deflated, the structure must be so designed that any tube is divided by the folds into two equal halves. This feature determines the relationship of the length of the carry-over threads which constitute the partitions or diaphragms to the distances they are spaced apart from each other. Hence throughout the whole structure, the following proportions must be true: AB plus BJ equal AK plus KJ; DE plus EG equal GH plus HD, and the same for each individual tube or cell. And so it follows that AKJIHGF=ABCDEF As the desired shape is comparatively short and the surrounding tube is bent in a different manner at different places and also containing straight portions, it is preferable to shape the tube by shaping the fabric. The pattern under discussion is shown in Fig. 12 and may be woven on a Jacquard loom or sewn with seams that are curved.

The geometrical configuration can be made clear by referring to the cross-section formed by the tubes 63 and 64 as a generatrix, and moving it along a predetermined outline of the boat, while the other part of the cross-section formed by the tubes 65, 66, and 61 remains straight and disappears when meeting the curved portion of tube 64. This form of invention also shows how all the cells may differ in contour and yet be formed by the present method.

When an uplift bow and stern are desired, a varying elongation of the fabric as between the points G and K of the cross-section may be provided, as p eviously described.

It is obvious that the entire unit for a comalong line A. In such case, only the ends of the surrounding structure need be united after folding on line A, to complete a seamless boat.

As in the example illustrated in Figs. 1, 2, 3, and 4, the structure may be subdivided in as many independent inflatable units as desired by the same means as discussed above: by subdividing the inflatable units along any of the diaphragms or partitions shown in Figs. 10, 11, and 12, which may form a bulkhead in the same manher as previously described. The entire unit or component part is then combined to airtight material on both sides to encase it completely. Then two such half structures or units are combined to form a boat.

It may be desirable to produce an inflatable boat that is still nearer to the traditional shape.

scribed. While the above-described boat was made up of two halves each formed by the sidewalls combined with half the inflated bottom, the cross-section represented in Fig. 13 shows two independent surrounding tubes combined with an independent bottom unit 13.

Fig. 14 shows how the shape, represented in in Fig. 14a. The conical ends of the air chambers represented by the lines 16 may be tucked in so that the parts 16 assume positions 1| and 12.

scribed and shown as being in single straight lines, it will be obvious that they may be folded or doubled upon themselves, as has already been described with respect to the bulkheads 16, or as calender, as described above, will unite the right areas between the lines 19 and 18 duces, with one mechanical operation, a boat that simulates the one represented in Figs. 10, 11, and 12. However, it is built up of parts difits upward bending. But, as its thickness is comparatively small, this bending may be obtained by the natural elasticity of the fabric. Of course, the flat inflated bottom unit can be substituted by a single fabric bottom unit folded along the line 11 and with the outline 18.

Another method of making relatively short boats will be now described. Such a method is disclosed in Figs. 17, 18, 19, 20, and 21.

It will be noted that the completed boat, in the above forms and best seen in Figs. 2 and 11, is substantially V-shaped when deflated and lies flat as can be understood. When constructing a boat of the proportional form shown in Fig. 4, the V-shaped construction may be readily followed.

This condition is exaggeratedly illustrated in Figs. 18 and 19 where is the edge of fold and BI th keel line. It will be seen, that upon inflation of the boat, the line 80 will seek to stretch and the line 8| to shrink.

Resort is, therefore, had to a W-shaped structure. As seen in Figs. 20 and 21, the keel line 82 is now comparable in length to the chine 83 and stresses in the fabric are reduced. In Fig. 21, lines 82, 83 and 83' are now approximately the same length.

Fig. 17 reveals such a structure which is formed as heretofore described, the cells 84 and 85 being comparable to the like cells on the previous forms and the cells 86 comparable to cells 4| and 64. The latter cells are the ones which form the chine as can be understood so that the cells 84 I form the boat sides. p 7

It will, therefore, be seen that though the boat when deflated, is iniolded flat condition'it will, nevertheless, when inflated, open up so that the bottom, which is in iolded parts, will extend to producea substantially flat bottom It is obvious that this shape' rnay be combined with the weaving of diiferent lengths and that the combination can give any desired result up to the circular form which hardly will be desired.

The foregoing describes anovel form of inflatable boat in various a novel method for constructing the same. Itis obvious that the invention may be practiced'in various ways within the spirit of the invention other than those described. No limitation, as regards the following claims, is intended by the specific terms used in the description.

I claim:

1. An inflatable boat having bottom and sides comprising two joined symmetrical units, each unit comprising. two superimposed sheets of fabric of predetermined elongated shape, and enveloped between two layers of air-impervious mate rial which are united at their edges to formthe. unit, one layer constituting the ultimate outside and the other the ultimate inside of half of a fin ishedboat, interconnecting means extending betweenv the sheets from the sheet adjacent the outside layer toward the sheet adjacent the inside layer in a direction inwardly from the longi tudinal edges of the layers so that the interconnections form compartmentsibetween the sheets, the intermediate compartment which has converging interconnections forming the ultimate bottom and the cells 85 the boat chine of the boat, said units being united along a substantial area adjacent the contiguous edges from end to end along the keel line to'form a complete boat.

2. An inflatable boat having bottom and sides comprising a plural'ty of units, each unit comprising two superimposed sheets of fabric of predetermined elongated shape, and enveloped. in a casing of air-impervious material, which sheets are united at their side of the casing to form the ultimate outside and the other side of the, casing the ultimate inside of a section of a finished boat, at least two of said units having interconnections extending between the sheets, from the sheet adjacent the one side of the casing toward the sheet adjacent the said other side'oi the casing in'a direction away from the longitudinal edges of the sheets so that the interconnections form compartments between the sheets, the intermediate compartment which has the interconnections running in opposite directions forming the ultimate chine of the boat, all of said units being united along an area adjacent the edges of each unit to a similar area on another unit completely around their perimeters except those portions which surround the-opening to the boat to form a complete inflatable boat.

3. An inflatable boat having bottom and. sides and made up of a plurality of units, each unit comprising two superimposed flat-lying air-impervious sheets united along their edges while in flat condition, and the units being united to each other by joining the adjacent units along a substantial area, the outline of the united units including the contour of the gunnel or sheer, the bow and the stern profiles of the collapsed boat, and all of the units together forming the sides forthe boat.

forms of conception and edges to form the unit,'one

consisting of 10" and bottom of the boat, and said boat bein adapted to lie flat when deflated.

4. The method of makinginfiatable boats having bottom and sides and collapsible to flat condition along a longitudinal medial plane, which consists inproducing a plurality of units consisting of flat sheets of material, some at least those intended for the boat sides, being inflatable and contoured so as to provide the gunnel or sheer, the bow and the stern profiles and all the units togetherforming the sides and bottom of the finished boat; superimposing these units in the flat so that together they produce the outline of the collapsed boat; adhesively uniting portions of the side units to form the bow and the stern,-and uniting an area along all the remaining edges of each unit, except for those porti-ons of the perimeter whichare to form the top opening of the boat, to corresponding areas on another unit.

5. The method of making inflatable boats having bottom and sides and collapsible to flat condition along a longitudinal medial plane, which consists in producing a plurality or fabric units flat sheets of material, some of which units, at least those intended for the boat sides, being inflatable and. contoured so as to provide the gunnel or'sheer; the bow and the stern profiles, and all the units together forming the sides and bottom of the finished boat, and while these sheets are in flat condition, making them waterand air-impervious by applying vulcanizable layers to encase each said unit; superimposing these units in the fiat so that together they produce the outline of the collapsed boat; ad hesively uniting the portions of the side units to form the bow and the stern, and uniting an area along all the remaining edges of each unit, except for those portions of the perimeter which are to form the top opening of the boat, to corresponding areas on another unit, and then vulcanizing the entire assembly.

6. A method of making inflatable boats which consists in making two inflatable units, each unit representing one longitudinal half of a boat, and having the outline representing the longitudinal profile of the boat when deflated, said units being composed of'superimposed sheets of flexible air-impervious material sealed or integrally united at their edges to form an inflatable unit, providing interconnections between the sheets at predetermined edges thereof, to serve, upon inflation, to limit the expanding of the portions between the intercon- 'metrical units, each unit comprising nections, some of the interconnections being disposed so as to allow a wider area between them on the outside of the boat than betweenthe same interconnections on the inside of the boat, to form the desired chine of the boat; then uniting the two units or halves of the boat, while both are superimposed in flat-lying condition, along their edges which are to represent the keel, the bow and the stern, and for a width equal to the thickness desired for the bow, stern, and bottom of the longitudinal medial plane of '7. The method of making having bottom and sides and when deflated, which consists in making two symtwo coextensive layers joined together all around their perimeters' to make an inflatable unit to form the sides of the boat, said perimeter including the subsequent sheer, bow, and stern profiles; making an additional unit for the boat bottom, fold ing said bottom in half longitudinally, and unit-- of which units,

12 ing the bottom to the sides by laying one upon the the other sheet, the part of either sheet having other in flat condition with the fold line upwardthe greater spaces between the interconnections,

ly and adhering one-half of the bottom rim to becoming the outcurve portion of the boat when one side unit and the other half to the other side inflated. unit, then uniting the corresponding, respective 13. The method set forth in claim 4 in which ends of the sides by adhering superimposed porthe sheets of at least one of the units are intertions thereof, said fold line of the bottom being connected at spaced intervals by a plurality of so disposed that it connects a point on the outline interconnections between the sheets to limit their of said portion at the bow to a point on the outspaced-apart relation when the unit is inflated, line of said portion of the stern. said interconnections being secured to the respec- 8. The method of making an inflatable boat tive sheets along lines, all of which are straight having a flat bottom, and a surrounding tube, and parallel. which consists in folding a water-impervious flat 14. The method set forth in claim 4, in which bottom upon itself along its longitudinal medial at least one of said units has a series of overline, applying and uniting to the peripheral edges lapped tubular members sandwiched between the of each fold of the bottom a waterand air-inn sheets forming the units, those portions of the pervious flat-lying tubular member, the contours tubes which are overlapped being adhered and of which, when deflated, are curved to produce constituting interconnections between the sheets the desired shape of the boat; the peripheral when inflated to limit the spaced apart relation edges of the bottom having been previously and control the shape of the inflated unit,

shaped so that their contours when lying flat be- MethOd of p od fla a e articles tween the flat-lying tubular members, lie within o t t t by a p u y f lar its in the confines of said tubular members, and unit- Which e unit is brought 1 a at position S0 ing the respective ends of the tubular members in that both halves of the circumference of the tube the medial plane. are separated by two foldlines, and on one half of 9. An inflatable boat having bottom and sides one unit two other units are superimposed and and collapsible when deflated to flat condition a h in ver apped arran ements, each on the and comprising a plurality of inflatable flat-lying same face of the first uni-t along two portions coextensively in flat condition and joined toa n inflation When t na h d Pa ts of gether to produce a foldline at at least each joint, l units form Cylindrical Surfaces, e planes one of said folds being on a vertical lane runnin through the axes of the cylinders form an angle through the longitudinal medial line of the inhaving its apex in the axis f the un t a in flated boat, the contour of the flat-lying asse'inboth other units adhered 0n the Same facebly including the sheer, bow and stern profiles of 16. An inflatable boat having bottom and sides the deflated boat. and made up of a plurality of units, each unit compnsing two Joined cOeXtensive n t which pervious sheets united along their edges and said lit flat when deflated, each unit being inflatable Sheets being er un ted by means of interand so contoured as to provide th gunne] or 40 connections between the sheets, and the units besheer, the keel llne and the bow and stern promg united 0 each other y Jolmng J e ufllts fil s, a plurallty of interconnectin mean ithalong a, substantial area the entire boat being in the unit walls, said mean xt from hnes adapted to lie flat when deflated and each unit on one wall inwardly to lines nearer the center being so constructed a ra d that W en inof the other wall so that the interconnections flated a transverse cr -sec on w d p t a form compartm t th b t th t series of intersecting circles with the intercondiate compartment wh ch h converglng t nectlons serving as common chords between the area adjacent the contiguous edges of the stem, length, and with a line extending through the unit comprising two superposed layers of predecenters of the said first circle and the 1ntersect termined identi l h the perimeter f which ing circle common to its other chord, the outside includes the gunnel o1 sheer and at least portions circles esenting Qne are and one ch01 d While unit folded upon itself, the fold constituting the and two chordsultimate ke l li and it t two halves of 17. Method for producing inflatable structures the ultimate outside face of the additional unit Consisting Of two or more units, wherein each unit confronting each other, the edges f the unit on consists of a pair of configural sheets of flat mathe ultimate inside of th said additional unit n terial superimposed one upon the other and united the fold line upwardly, said additional unit conwherein at least one of said units has interstituting at lea t a portign of t bottom f the connections between the sheets attached along inflated boat. lines to each sheet to form rows to limit the ex- 12. The m th t forth in claim 4 in which pansion of the article upon inflation between said the sheets of at least one of the units are inte lines of attachment to the length of the interconnected at spaced intervals by a plurality of connections and allows the portions between said connections on one sheet being diirerent from uniting them along a portion of the adjacent surthe spaces between the same interconnections on face of each unit so that upon inflation said porarticle the planes described throughthe axis of the cylinder having unequal cylindrical portions and the axes of the. two adjacent cylinders form an angle having its apex on the axis of the cylinder having the. unequal cylindrical portions.

18. In an inflatable structure having two superimposed flat. sheets or, material united sub stantially around their edges as well as by interconnecting means disposed in rows and attached along: lines to each. of the sheets with the interconnecting means being so dimensioned as to allow the structure to assume a flat condition when deflated and" when inflated to allow the portions of the sheets between the lines of attachment plete cylinders with the interconnecting means constituting chordal' planes common. to adjacent cylinders, a. first incomplete cylinder having two non-parallel chordal planes, a second incomplete cylinder having at least one chordal plane which is contiguous and coextensive with and common to a chordal plane of the first incomplete cylinder, a third and a fourth incomplete cylinder each having two parallel chordal planes one on each side of its axis, one of said chordal planes of the third cylinder being contiguous and coextensive with and commonto the other of the chordal planes of said first incomplete cylinder andv the other of its chordal planes being common with that of the fourth: cylinder, all of said incomplete cylinders being so disposed relative to each other that'when-i-nflated, an extended, plane passing through the: axes of the third and fourth incomplete cylinders forms an angle with the plane passing through the axes of the first and second incomplete cylinders.

19; The method of producing inflatable articles of a plurality of units, each unit of which is made up or a plurality of tubular members which consists in flattening all the members, in superimposing and adhering a second member upon a first member to lie substantially parallel to the first member in overlapping offset: arrangement, overlapping and adhering a thirdmember to the second member in the same manner so that when the so formed unit is inflated a series of incompl'ete cylinders are formed, the adhered portions formingchordal planes, each common to a pair of adjacent cylinders, substantially closing the units around their perimeters, superimposing two such symmetrical units, and adhesively uniting them on a band adjacent acoextensiveportion or their edges, sothatthis: band unites at least the last member of each unit and the uniting band forming a chorda'l surface common to each pair of symmetrical cylinders covered by the band so that the folded V-lilre structure will open'up upon inflation to form a body composed of all the members arranged in one'continuous surface.

20. The method of producing inflatable articles which comprises a plurality of tubes, which consists in flattening the tubes, superimposing upon and adhering to one of the tubes two other tubes on the same face. of the first tube so that the second and third tubes extend outwardly in op-..

posite directions from said first tube,then superto form cylindrical. surfaces of incom- 1.4 imposing and; adhering part of a fourth. tube uponpart of the upper face or the third tube and-extending. outwardly therefrom, so that upon inflation the unadhered parts of all the tubes assume cylindrical surface forms, and the. adhered portions. form chordal planes between the intersecting cylinders, and the plane extending through the axesof the third and'fourth cylinders forms an. angle. with the plane extending through theaxes of; the first and second cylinders.

21;. An inflatable'boat having bottom and sides and collapsible to flat condition, and comprising two or ,more units, each unit comprising two superimposed impervious sheets of predetermined shape, one sheet constituting the ultimate out.- side and the other sheet the ultimate inside. of a part of a. finished'boat, connecting means extending. between. the sheets and so disposed as to permit; the. sheets. to lie flat upon each other, all-of saicl unitsrbeing united along a substantial area adjacent theedges of each unit to a similar area: on another unit, completely around their perimetcrs except for those portions which surround the opening to-the boat, to form a complete inflatable boatfsaicl united areas constituting additional connecting means between the inside of, theboat and the outside of the boat, the space between some of the connecting'means on the inside of the boat being diiierent from the space between. the same connecting means on" the outside ofthe boat, those portions: which have-thenon-uniformly spaced connections defining the'bent portions of any'section of themflated boat. 22. The method of making inflatable boats havingbottom and, sides and collapsibleto flat condition along a longitudinal medial plane, whicheonsists in producinga plurality of units consisting, of flat sheets of material, some of whichunits, atleast thoseintended for the boat sides, being inflatable. and contoured so as to provide-at least part of the outline of the collapsed boat, and all the units together forming the sides and bottom or the finished boat; superimposing these units in. the flat so that together they produce the outline of the collapsed boa-t; uniting portions or the side'units to form the bow and the. stern profiles, and uniting an area along all the: remaining edges of each unit, except for those; portionsof the perimeter which are to form the top opening of the boat, to corresponding areas on another unit.

23;. The method of making inflatable boats having. bottom; and: sides and collapsible to flat condition along a: longitudinal medial plane, which consists inproducing a plurality'of fabric units consisting of flat sheets of material, some of which units, at least those intended for the boat sides, being, inflatable and contoured so as to; provide at least part of the outline of the collapsed boat, and all'the units together forming the sides and bottom of the finished boat, and whil-ethese sheets are in flat condition, making them waterandair-irnpervious by applying vulcan zablelayersto encase each said unit, super imposing these" units in the flat so that together they produce the outline of the collapsed boat; uniting the portions of the side units to form the bow and the stern profiles, and uniting an area along all the remaining cept for those portions of the perimeter which are to form the top opening of the boat, to corresponding areas on another unit, and then vulcanizing the entire assembly.

24. An inflatable structure or part thereof edges of each unit, ex

a limited each Weave pattern and so arranged that a section of equal length in deflated condition of each of said portions, will when inflated, assume various lengths, proportional for each portion, to the mean distance of this portion from the bending 25. An inflatable structure formed by two laysubstantially around their to bend, upon inflation, around an axis which forms an angle with a plane through the edges of said layers, portions of both said layers being located at different distances from said bending axis, and being separated from each other by various lengths, proportional, to the mean distance of that portion from the bending axis, so that upon inflation the structure will bend, the center of the bending curve being said bending axis,

26. An inflatable structure or part thereof that the ultimate length of a said portions having equal lengths in deflated condition will assume variouslengths when inflated, proportional, for each portion, to the mean distance of that portion from the bending 27. An inflatable boat having bottom and sides and made upof a plurality of units, each unit being composed of a plurality of flattened tubular members superimposed and united in the fiat on a substantial area along at least one edge of each tubular member to a superimposed area of another tubular member, half of the perimeter of the ends of each tubular member being joined AUGUST G. LUISADA. 

